It adopts multi-tower series continuous high vacuum precision rectification technology, which is combined with extraction, evaporation, stripping and other units depending on the material conditions. The main core equipment involved in this technology is extraction column, stripping column, rectification column, evaporator, vacuum system and heating and condensation system. The purity of the recycled product is ≥99.5%; the water content of the product is <100ppm; and the metal ion content of the product is <5ppb. The solvent consumption of related enterprises is reduced by 50-200m3/day. The water content of recycled products is less than 100ppm, and the external discharge of waste liquid from enterprises is significantly reduced.